BEIRUT/BAGHDAD/UNITED NATIONS - The Islamic State group has abducted 230 civilians, including at least 60 Christians, in a central Syrian town hours after it captured it, a monitoring group said on Friday.

The Syrian Observatory for Human Rights said the civilians were taken on Thursday in the town of Al-Qaryatain, which IS militants had captured late Wednesday.

“Daesh kidnapped at least 230 people, including at least 60 Christians, during a sweep through Al-Qaryatain,” Observatory chief Rami Abdel Rahman said, using another name for IS.

Bishop Matta al-Khoury, secretary at the Syriac Orthodox Patriarchate in Damascus, told AFP he could not confirm what had happened in the town “because it’s very hard to reach residents now”.

“But we know that when IS entered the town, it forced some people into house arrest... to use them as human shields” against regime air strikes, Al-Khoury said. According to Abdel Rahman, many of the Christians had fled from the northern province of Aleppo to seek refuge in Al-Qaryatain. He said those abducted were wanted by IS for “collaborating with the regime,” and their names were on a list used by the militants as they swept through the town. Families who tried to flee or hide were tracked down and taken by the militants, he said.

Al-Khoury urged IS to allow residents who want to leave the town to depart. Al-Qaryatain lies at the crossroads between IS territory in the eastern countryside of Homs and areas further west in the Qalamun area. It had a pre-war population of 18,000 and around 2,000 Syriac Catholics and Orthodox Christians. Al-Khoury said only 180 Christians were in the town when IS seized it.

In May, masked men abducted Syrian priest Jacques Mourad from the Syriac Catholic Mar Elian monastery in Al-Qaryatain, near the IS-captured ancient city of Palmyra. Mourad, who was known to help both Christians and Muslims, was preparing aid for an influx of refugees from Palmyra.

In a rare display of cooperation between the U.S. and Russia, the United Nations Security Council Friday approved the establishment of a Joint Investigative Mechanism to identify those responsible for the use of chemical weapons in Syria.

Russia, Syria’s veto-wielding ally on the Security Council, agreed to endorse the measure in the vote. It paves the way for a probe over who is responsible for chemical attacks, a contentious issue and still subject to debate. While the 15-member council cannot hold perpetrators criminally responsible, identifying them will allow for prosecutions in the future.

Samantha Power, US Ambassador to the United Nations, said afterwards that the accountability mechanism adopted by the Security Council will end impunity. “The joint investigative mechanism will identify you if you gas people,” Power said. “Pointing the finger matters.” To date, a total of 1,300 metric tons of chemical stockpiles have been surrendered by the Syrian government and neutralized by the US Navy.

The Islamic State group has executed more than 2,000 people in and around the northern Iraqi city of Mosul since seizing it last year, officials said Friday.

Parliament speaker Salim al-Juburi confirmed “the execution of more than 2,000 innocent citizens at the hands of the terrorist Daesh organisation,” his office said, using an Arabic acronym for IS.

Meanwhile, the UN Security Council voted unanimously Friday to set up a panel to identify who is behind deadly chlorine gas attacks in Syria, which the West blames on the Damascus regime.

Russia, Syria’s veto-wielding ally, endorsed the measure as did the rest of the 15-member council - a rare display of unity over how to address the conflict, which has left more than 240,000 people dead.

Under discussion for months, the US-drafted resolution sets up a team of experts tasked with identifying the perpetrators of the chemical weapons attacks and paves the way for possible sanctions to punish them.

The United States, Britain and France have repeatedly accused President Bashar al-Assad’s forces of carrying out chlorine gas attacks with barrel bombs dropped from helicopters.

The three countries argue that only the Syrian regime has helicopters. But Russia maintains there is no solid proof that Damascus is behind the attacks.

Both Russia and the United States, divided over the war since it broke out, welcomed the resolution.

“We need to bring the same unity to urgently find a political solution,” US ambassador Samantha Power said, adding the resolution “sends a clear and powerful message.”

In a tweet, she called the probe panel a necessary step toward “eventual accountability.”

Russian ambassador Vitaly Churkin said the resolution was “a good example of political will, of the will to cooperate and of perseverance to come up with a good product.”

The investigative panel will be given “full access” to all locations in Syria and allowed to interview witnesses and collect materials, according to the text of the resolution.

It mandates the panel to “identify to the greatest extent feasible individuals, entities, groups or governments who were perpetrators, organizers, sponsors or otherwise involved in the use of chemicals as weapons” in Syria.

UN Secretary-General Ban Ki-moon is tasked with assembling the team within 20 days, working with the Organization for the Prohibition of Chemical Weapons (OPCW), which is based in The Hague.

The panel would present its first findings to the council 90 days after it begins its work, which would be for a duration of one year.

Questions remain however over whether panel members will be able to travel to sites in a country where war is raging and gain evidence of chlorine attacks that would allow them to assign blame.

Getting the panel up and running will require several steps, each of which must be approved by the Security Council, giving Russia the opportunity to stonewall the investigation down the line, diplomats said.

Syria’s UN ambassador Bashar Jaafari said his country’s army “has never used and will never use chemical weapons.”

He said extremist groups linked to al-Qaeda have done so, and he questioned the neutrality of previous on-the-ground probes by the UN and the OPCW.

Pressure has been mounting on the Security Council to take action in Syria, where the war is now in its fifth year. It tops the UN’s list of humanitarian crises.

Russian support for the chlorine attacks probe is seen by some western diplomats as a shift from Moscow, which has repeatedly shielded the Assad regime at the United Nations.

“There is a change of tone,” one Council diplomat said this week, while cautioning: “I don’t want to overstate it.”

Diplomats are separately working on a council statement backing a new push for UN peace talks that could yield a plan for a transition that the West insists must lead to Assad’s exit from power.

Discussions are inching forward on a new tougher UN measure to ban the use of barrel bombs, building on resolutions that have condemned the practice.

Syria agreed to a US-Russia plan to dismantle its chemical weapons network and join an international treaty banning their use following a 2013 sarin attack on a Damascus suburb that sparked a global outcry.

The United States threatened military action against Damascus over the attack, but held off following the chemical disarmament agreement.

A total of 1,300 metric tonnes of chemical stockpiles have been removed from Syria under the deal.

But rights groups and Syrian doctors have since come forward with accounts of dozens of chlorine gas attacks that have in particular targeted Idlib province.